Anti-bacterial metallo ionomer polymer nanocomposite filaments and methods of making the same

ABSTRACT

A composite filament includes a core particle comprising a styrene/acrylate polymer resin, and a shell comprising a styrene/acrylate ionomer resin, wherein the styrene/acrylate ionomer resin comprises a metal ion acrylate monomer, and methods of making thereof. Various articles can be manufactured from such composite filaments.

CROSS-REFERENCE TO RELATED APPLICATIONS

Reference is made to commonly owned and co-pending, U.S. patentapplication Ser. No. ______ (not yet assigned) entitled “ANTI-BACTERIALMETALLO IONOMER POLYMER NANOCOMPOSITE POWDERS AND METHODS OF MAKING THESAME” to Valerie M. Farrugia et al., electronically filed on the sameday herewith (Attorney Docket No. 20151081US01-445113), the entiredisclosures of which are incorporated herein by reference in itsentirety.

BACKGROUND

The present disclosure relates to composite filaments, particularly,filaments of metallo ionomer polymer nanocomposites, wherein thecomposite nanoparticle comprising a core and a shell. The nanocompositescan be use in Fused Deposition Modelling (FDM).

There is a growing interest in embedding nano-metals in polymer matricesbecause of antimicrobial and conductivity properties (thermal andelectrical). By combining the properties from both inorganic (i.e.,silver, gold, copper etc.) and organic (polymer) systems, new compositeproducts can be generated that find expanded use in antimicrobialapplications, thermal and electrical conductivity applications, and soon.

The medical community's reliance on three dimensional 3D printing forvarious applications is rapidly increasing and covers areas such astissue and organ fabrication, customizable devices such as prosthetics,mouth guards, orthotics, hearing aids and implants, and pharmaceuticalexploration related to controlled drug delivery and personalized drugproduction. Many of these medical applications require compositematerial that can inhibit bacterial, microbial, viral or fungal growth.Other products for 3D printing such as kitchen tools, toys, educationmaterials and countless household items also provide a favorableenvironment for bacteria growth, and therefore antibacterial compositematerials are also desirable for use in connection with these products.Due to the layered construction of 3D printed material, the potentialfor bacterial growth can be very significant, especially since certainbacterial strains can actually thrive within the detailed structuralmake-up of these materials. Washing alone does not completely sterilizethe surfaces and crevasses of these products.

Therefore, there exists a need for new materials with antibacterialproperties for 3D printing. One of the 3D printing methods is FDM, whichis a common additive manufacturing (3D printing) technique. FDM is anadditive layer manufacture technology for fabricating physical, 3Dobjects from computer-aided-design (CAD) models. FDM technology canprocess common 3D printing materials, such as, polylactic acid (PLA),acrylonitrile butadiene styrene (ABS), and high-density polyethylene(HDPE). FDM operates on the principle of heating and then extruding afeedstock material, typically as a series of stacked, patterned layers,thereby to form a build. FDM process employs moltenthermoplastic/polymers as build materials for making 3D articles via theextrusion of the molten plastics. This modelling process is a multi-stepapproach where a computer-aided design is rendered, in the case ofmedical applications this model would come from an ultrasound, computedtomography scan or magnetic resonance image. This design is thenprocessed by software which sets the desired build parameters. The filedata is used by the FDM apparatus to build the article. The spool offilament material is fed into a headed extrusion head which delivers thesemi-liquid material onto the build platform in a layer-by-layerfashion. As the model is built, the layers solidify upon deposition dueto the temperature differential of the build chamber. In some cases thehead can also extrude a removable support material which acts as ascaffold to hold the article layers in place as it cools. This supportmaterial can later be removed via heating, breaking off or washing (inultrasonic vibration tank). A layer by layer method of depositingmaterials for building a model is described in U.S. Pat. No. 5,121,329which is incorporated herein by reference. Examples of apparatus andmethods for making three-dimensional models by depositing layers offlowable modeling material are described in U.S. Pat. No. 4,749,347,U.S. Pat. No. 5,121,329, U.S. Pat. No. 5,303,141, U.S. Pat. No.5,340,433, U.S. Pat. No. 5,402,351, U.S. Pat. No. 5,503,785, U.S. Pat.No. 5,587,913, U.S. Pat. No. 5,738,817, U.S. Pat. No. 5,764,521 and U.S.Pat. No. 5,939,008. An extrusion head extrudes heated, flowable modelingmaterial from a nozzle onto a base The base comprises a modelingsubstrate which is removably affixed to a modeling platform. Theextruded material is deposited layer-by-layer in areas defined from theCAD model, as the extrusion head and the base are moved relative to eachother in three dimensions by an x-y-z gantry system. The materialsolidifies after it is deposited to form a three-dimensional model. Itis disclosed that a thermoplastic material may be used as the modelingmaterial, and the material may be solidified after deposition bycooling.

SUMMARY

In some aspects, embodiments herein relate to composite filamentcomprising a core particle comprising a styrene/acrylate polymer resinand optionally a first metal ion acrylate monomer; and a shellcomprising a styrene/acrylate ionomer resin, wherein thestyrene/acrylate ionomer resin comprises a second metal ion acrylatemonomer; wherein the total amount of metal presented in the compositefilament ranges in a concentration of from about 0.5 ppm to about 50,000ppm; and further wherein the composite filament has a diameter of fromabout 0.5 mm to about 5 mm.

In some aspects, embodiments herein relate to method of producing acomposite filament, the method comprising polymerizing a first mixturecomprising a first styrene/acrylate copolymer to form a corestyrene/acrylate polymer resin in an organic-free solvent; heating thecore styrene/acrylate polymer resin; adding a shell styrene/acrylateionomer resin by polymerizing a second mixture comprising a secondstyrene/acrylate copolymer and initiator to the formed polymer corestyrene/acrylate polymer resin to form a shell disposed about the corestyrene/acrylate polymer resin, thereby forming an emulsion of compositeparticles, wherein the shell styrene/acrylate ionomer resin comprises ametal; aggregating the emulsion of composite particles to formaggregated particles; coalescing the aggregated particles to formcoalesced particles; washing the coalesced particles, thereby formingthe composite powder; and extruding the composite powder to produce thecomposite filament.

In some aspects, embodiments herein relate to an article comprising acomposite filament comprising a core particle comprising astyrene/acrylate polymer resin and optionally a first metal ion acrylatemonomer; and a shell comprising a styrene/acrylate ionomer resin,wherein the styrene/acrylate ionomer resin comprises a second metal ionacrylate monomer; wherein the total amount of metal presented in thecomposite filament ranges in a concentration of from about 0.5 ppm toabout 50,000 ppm; and further wherein the composite filament has adiameter of from about 0.5 mm to about 5 mm.

BRIEF DESCRIPTION OF DRAWINGS

Various embodiments of the present disclosure will be described hereinbelow with reference to the figures wherein:

FIG. 1 shows schematic representations of ionic crosslinks betweenionomer-type polymers according to certain embodiments described herein.

FIG. 2 shows a schematic of mechanism of bulk emulsion polymerization oflatex particles containing Ag-based monomer according to certainembodiments described herein.

FIG. 3 shows a schematic of a possible mechanism of the preparation ofdry particles for filament fabrication.

FIG. 4 shows a photo image of a dish containing silver methacrylatelatex-suspensions synthesized from Example 2 (top half) and Example 3(bottom half) being placed on two different substrates after incubation.

DETAILED DESCRIPTION

As used herein, “a,” “an,” “the,” “at least one,” and “one or more” areused interchangeably. Thus, for example, a coating composition thatcomprises “an” additive can be interpreted to mean that the coatingcomposition includes “one or more” additives.

Also herein, the recitations of numerical ranges includes disclosure ofall subranges included within the broader range (e.g., 1 to 5 discloses1 to 4, 1 to 3, 1 to 2, 2 to 4, 2 to 3, . . . etc.).

The term “ionomer,” as used herein, refers to a polymer having covalentbonds between elements of the polymer chain and ionic bonds between theseparate chains of the polymer. An ionomer is also known to be polymerscontaining inter-chain ionic bonding. An ionomer is a polymer thatcontains nonionic repeating units and a small portion of ionic repeatingunits which are usually pendant to a polymer backbone. Thus, an ionomercontains both ionic and covalent bonds. Covalent bonds exist along thepolymer backbone chains. Ionic groups are attached to the backbone chainat random intervals. Depending on the ionomer morphology such asfraction and spacing of ionic functional groups, dielectric constant ofthe polymer matrix, chemical structure of the acid copolymer and localchemical conditions, such as pH, temperature, cation size or type (Zn,Ba, Cs, Cu, Na, Mg), dielectric matrix concentration, the ionic groupsalong the polymer backbone can form strong electrostatic interactionsbetween other ionic groups which lead to nanoscale aggregation orphysical crosslinks. These crosslinks enable significant improvement inthe physical and chemical properties of ionomers compared to theirnon-ionic counterpart polymers.

The term, “metal acrylate(s),” such as, “silver acrylate(s),” as usedherein, is collective for acrylate monomers comprising at least onemetal atom, such as, a silver atom, for use in polymers, such as, silveracrylate and silver methacrylate which are monomers for a polymercomprising silver.

The term, “antibacterial,” as used herein refers to the property of acomposition for inhibiting or destroying the growth of bacteria. Inother words, a toner particle comprising antibacterial properties iseffective in killing bacteria, or in inhibiting growth or propagation ofbacteria, including as a printed or fused image.

The term, “antimicrobial,” as used herein refers to an agent, or theproperty imparted by the agent, that kills or inhibits growth ofmicroorganisms or microbes. An antibacterial agent, or property thereof,is an antimicrobial agent. Microorganisms include, for example,bacteria, fungi, algae, other single celled organisms, protists,nematodes, parasites, other multicellular organisms, other pathogens andso on. In other words, a toner particle comprising antimicrobialproperties is effective in killing microbes, or in inhibiting growth andpropagation of microbes, including as a printed and fused image.

The term, “nano,” as used in, “silver nanoparticles,” indicates aparticle size of less than about 1000 nm. In embodiments, the silvernanoparticles have a particle size of from about 0.5 nm to about 1000nm, from about 1 nm to about 500 nm, from about 1 nm to about 100 nm,from about 1 nm to about 20 nm. The particle size is defined herein asthe average diameter of the silver nanoparticles, as determined by TEM(transmission electron microscopy). In embodiments, the compositenanoparticle has a volume average particle diameter (D50) of from about10 to about 600 nanometers, or from about 10 to about 300 nanometers, orfrom about 10 to about 200 nanometers.

The present disclosure provides a metallo ionomer polymer nanocompositefilament material for use in Fused Deposition Modelling (FDM)application.

The metallo ionomer polymer nanocomposites are metallo ionomer polymerlatex (also refers to herein as “composite latex”) that contain a coreand a shell. In embodiments, the shell comprises an ionomer. Inembodiments, the core comprises an ionomer. In embodiments, both theshell and the core each comprise an ionomer. In embodiments, the corecomprising at least one styrene/acrylate polymer resin, optionallycomprising a first metal ion acrylate monomer. In embodiments, the shellcomprising a styrene/acrylate ionomer resin (or styrene/acrylate metalion polymer resin).

The metallo ionomer polymer nanocomposites may be prepared by emulsionpolymerization. The emulsion polymerization technology may be used toincorporate a metal monomer into a polymer chain to provide addedfunctionality to the metallo ionomer polymer latex. The metallo ionomerpolymer latex may then be aggregated into micron-sized particles thatare dried into a powder (hereinafter “composite powder”) by a processsimilar to the emulsion aggregation (EA) for preparation of certain 2D(two-dimension) toner powders, and then further processed into afilament structure for use in FDM applications.

Core particles may be synthesized in an emulsion polymerizationreaction, followed by polymerization of shell monomers on the surface ofcore particles.

In embodiments, the core resin comprises a silver composite monomerselected from the group consisting of a silver acrylate monomer, asilver methacrylate monomer, and combinations thereof.

The core resin may be synthesized using any of the styrene/acrylatecopolymer disclosed herein or known in the art. Examples ofstyrene/acrylate copolymer include, but are not limited to, styreneacrylates, styrene butadienes, styrene methacrylates, and combinationsthereof. In embodiments, are provided core resin particles wherein thepolymers are selected from poly(styrene-alkyl acrylate),poly(styrene-1,3-diene), poly(styrene-alkyl methacrylate),poly(styrene-alkyl acrylate-acrylic acid),poly(styrene-1,3-diene-acrylic acid), poly(styrene-alkylmethacrylate-acrylic acid), poly(alkyl methacrylate-alkyl acrylate),poly(alkyl methacrylate-aryl acrylate), poly(aryl methacrylate-alkylacrylate), poly(alkyl methacrylate-acrylic acid), poly(styrene-alkylacrylate-acrylonitrile-acrylic acid),poly(styrene-1,3-diene-acrylonitrile-acrylic acid), poly(alkylacrylate-acrylonitrile-acrylic acid), poly(styrene-butadiene),poly(methylstyrene-butadiene), poly(methyl methacrylate-butadiene),poly(ethyl methacrylate-butadiene), poly(propyl methacrylate-butadiene),poly(butyl methacrylate-butadiene), poly(methyl acrylate-butadiene),poly(ethyl acrylate-butadiene), poly(propyl acrylate-butadiene),poly(butyl acrylate-butadiene), poly(styrene-isoprene),poly(methylstyrene-isoprene), poly(methyl methacrylate-isoprene),poly(ethyl methacrylate-isoprene), poly(propyl methacrylate-isoprene),poly(butyl methacrylate-isoprene), poly(methyl acrylate-isoprene),poly(ethyl acrylate-isoprene), poly(propyl acrylate-isoprene),poly(butyl acrylate-isoprene), poly(styrene-propyl acrylate),poly(styrene-butyl acrylate), poly(styrene-butadiene-acrylic acid),poly(styrene-butadiene-methacrylic acid),poly(styrene-butadiene-acrylonitrile-acrylic acid), poly(styrene-butylacrylate-acrylic acid), poly(styrene-butyl acrylate-methacrylic acid),poly(styrene-butyl acrylate-acrylonitrile), poly(styrene-butylacrylate-acrylonitrile-acrylic acid), poly(styrene-butadiene),poly(styrene-isoprene), poly(styrene-butyl methacrylate),poly(styrene-butyl acrylate-acrylic acid), poly(styrene-butylmethacrylate-acrylic acid), poly(butyl methacrylate-butyl acrylate),poly(butyl methacrylate-acrylic acid), poly(acrylonitrile-butylacrylate-acrylic acid) and combinations thereof.

A shell resin may be formed and then added to the core particle emulsionto form a layer encapsulating the core particles. A shell emulsion maybe added to the reactor containing optionally heated core particlelatex, which forms, “surface seeds,” on core resin particles. Followingformation of the core latex, an emulsion of shell monomers may beprepared and added to the emulsion of core particles wherein a shellcomprising composite styrene/acrylate—metal ion polymer resin can beformed covering a part of or encapsulating, that is, covering the wholeor entirety of the surface of core particles. In forming a shellemulsion, shell monomers, e.g., silver acrylate monomer, silvermethacrylate monomer, and combinations thereof, optional chain transfermonomer, optional chain branching monomers may be added to an aqueoussolution optionally comprising a surfactant. In certain embodiments, thesilver monomer is present in the shell resin in an amount of from about0.01 percent to about 10 percent, or from about 0.05 percent to about 8percent, or from about 0.05 to about 4 percent, by weight based on thetotal weight of the shell reins. In embodiments, the shell comprises astyrene/acrylate ionomer resin, wherein the resin comprises a co-monomerselected from the group consisting of methyl methacrylate, butylacrylate, diacrylate, cyclohexyl methacrylate, styrene, methacrylicacid, dimethylaminoethyl methacrylate or combinations thereof.

In embodiments, a shell resin is synthesized on core particles, whereinthe appropriate shell monomers and an initiator are added to the coreparticles. In embodiments, a metal ion is reduced on a resin or on acore particle to form a shell thereover. In embodiments, metal can bereducing during formation of a core. In embodiments, a metal can bereduced on a core. In embodiments, metal can be reduced on a shell. Ashell, such as, a resin comprising a metal or a reduce metal, forexample, may cover the entire surface of a core particle or portionsthereof. Hence, a shell can encompass the entire exterior surface of aparticle, thereby encapsulating a core particle or be found, forexample, at sites on the surface of a core, as isolated patches ofvarying size, islands and so on.

To complete polymerization of the core/shell resin, an aqueous solutionof initiator, such as ammonium or potassium persulfate, may be slowlyadded to the reactor. Following addition of all reactants, the emulsionmay be mixed and the heat maintained for an extended period of time,such as, about 6-24 hours. Following completion of the polymerizationreaction, the emulsion can be cooled and the resin particles may befiltered or sieved, such as with a 25 μm screen.

In embodiments, a metal ion acrylate or metal ion methacrylate monomermay be incorporated in a styrene/acrylate polymer via polymerization,that is, as a monomer that is covalently bound to another monomer toform the polymer backbone. In embodiments, the present composite ionomeris prepared by emulsion polymerization in a reactor, wherein an emulsionof at least one silver acrylate monomer, a styrene/acrylate co-monomer,an optional branching agent and an optional chain transfer agent isadded to a heated aqueous solution of surfactant. After reachingequilibrium, a solution of initiator can be added to the heated reactorand polymerization proceeds until completed. Formation of the latexcomprising the composite ionomers may be done in isolation, wherein theionomers optionally may be washed/screened/dried for future use, or alatex may be prepared as a multistep synthesis/polymerization of afurther resin-based material, such as, a composite nanoparticle, or forproduction of articles.

Incorporation of silver monomers in an ionomer, such as, with emulsionpolymerization, improves stabilization of the composite latex and alsoallows a controlled release of silver ions from the composite. Inaddition, the polymer backbone prevents the silver ions from aggregatingsince the silver ions essentially are bonded to and integrated in apolymer backbone and that enforces strict positioning of the silver ionsalong the polymer backbone for sensor or antimicrobial applications. Theionic polymer matrix provides a large active surface area of silver ionswhich can be spread strategically along the polymer backbone. Forinstance, the silver ions can be situated on the exterior shell of acore-shell nanoparticle for better exposure of metal ions to theenvironment.

Any metal ion acrylate monomer or methacrylate monomer useful forpolymerization of a styrene/acrylate latex resin may be utilized. Inembodiments, acrylic or methacrylic monomers may include, but are notlimited to, acrylate, methacrylate and so on, wherein the metal ionacrylate monomers are reacted with a styrene/acrylate monomer,optionally a branching agent, optionally a chain transfer agent andoptionally an initiator for synthesis of the present composite ionomerresin.

In embodiments, the optional core metal, if present, and the shell metalcomprise a composite comprising silver and one or more other metals;wherein the optional core metal, if present, and the shell metalcomprise a composite comprising silver and one or more non-metals; orwherein the optional core metal, if present, and the shell metalcomprise a composite comprising silver, one or more other metals, andone or more non-metals.

Silver is known for antimicrobial properties, however, for silver tohave any antimicrobial properties, generally, the silver must be ionized(Lok et al., J Biol Inorg Chem, 12:527-534, 2007; Rai et al., BiotechAdv, 27:76-83, 2009); non-ionized silver often is inert (Guggenbichleret al., Infec 27, Suppl 1:S16-23, 1999). It is thought silver atoms bindto thiol groups (—SH) in enzymes causing deactivation of the enzymes.Silver forms stable S—Ag bonds with thiol-containing compounds in thecell membrane that are involved in transmembrane energy generation andion transport (Klueh et al., J Biomed Mater Res 53:621-631, 2000). Italso is believed that silver can take part in catalytic oxidationreactions resulting in formation of disulfide bonds (R—S—S—R). Silvercatalyzes reaction between oxygen molecules in the cell and hydrogenatoms of thiol groups: water is released as a product and two thiolgroups become covalently bonded to one another through a disulfide bond(Davies & Etris, Catal Today 26:107-114, 1997). In addition, silver ionsmay interact with a cell destabilizing plasma membrane potential andreducing levels of intracellular adenosine triphosphate (ATP), resultingin cell death (Mukherjee et al., Theran 2014; 4(3):316-335). Silver isalso known for electrical and thermal conductivity properties. Theelectrical and thermal conductivity of silver is the highest of allmetals.

Those skilled in the art will appreciate that metals other than silvermay be useful and can be prepared in accordance with the methodsdisclosed herein. Thus, for example, composites may be prepared withnanoparticles of copper, gold, palladium, or composites of suchexemplary metals. See, for example, Adams C P, Walker K A, Obare S O,Docherty K M, PLoS One. 2014 Jan. 20; 9(1):e85981. doi:10.1371/journal.pone.0085981, eCollection 2014, describing palladium asan anti-microbial.

In embodiments, the filaments of the present disclosure further includesnanostructured materials, such as, without limitation, carbon nanotubes(CNTs, including single-walled, double-walled, and multi-walled),graphene sheet, nanoribbons, nano-anions, hollow nanoshell metals,nano-wires and the like. In embodiments, CNTs may be added in amountsthat enhance electrical and thermal conductivity.

In embodiments are provided methods for preparing metallo ionomerpolymer nanocomposite nanoparticles. Methods comprise forming coreparticles in an emulsion polymerization latex followed by polymerizationof a shell resin on the surface of core particles, wherein a core cancomprise a styrene/acrylate resin and a shell can comprise at least onecomposite styrene/acrylate—metal ion polymer resin. In embodiments, anemulsion of core monomers (styrene monomers, acrylate monomers, optionalchain transfer agent, and optional branching agents) is added to aheated solution of aqueous surfactant followed by addition of aninitiator. Core reactants are polymerized to form core styrene/acrylateparticles, optionally comprising a metal. Shell resin may be polymerizedon core particles by addition of shell monomers followed by addition ofan initiator. Following addition of a shell layer partially covering orencapsulating core particles, composite nanoparticles optionally may bewashed/screened/dried for future use, or a latex may be prepared as amultistep synthesis/polymerization of a further resin-based material,such as, for production of articles, such as, inks or toners. Inembodiments, both core and shell comprise metal ion resins.

In embodiments are provided articles comprising filaments of metalloionomer polymer nanocomposites comprising at least one metal ionacrylate monomer. In embodiments are provided articles comprisingfilaments of metallo ionomer polymer nanocomposites having a core and ashell, wherein the core comprises a styrene/acrylate resin, which cancomprise a metal, and the shell comprises at least one compositestyrene/acrylate—metal ion ionomer. An article may be selected from abiochemical sensor, an optical detector, an antimicrobial, a textile, afuel cell, a functional smart coating, a solar cell, a cosmetic, anelectronic component, a fiber, a cryogenic superconducting material andso on. In embodiments, composite nanoparticle and/or compositestyrene/acrylate ionomer resin is used as a resin in inks (aqueous anddry), toner, antimicrobial coatings, additives, finishes, paint,composites for 3-dimensional printing and so on.

Table 1 illustrates two of the key monomers that can be selected foremulsion polymerization of metallo ionomer polymer latex are silveracrylate and silver acrylate.

TABLE 1 Name Molecular Weight Silver Acrylate 192.95

Silver Methacrylate 178.93

Semiconductive electrical properties of the present silver ionomers wereanalyzed wherein ζ potential was measured. As understood in the art, ζpotential is a measure of magnitude of electrostatic or chargerepulsion/attraction between particles and is a fundamental parameterknown to impact stability. In other words, ζ potential, also referred toas electrokinetic potential, is an indirect measure or indicator ofstability of ionomer particle dispersion. For example, ζ potentialmeasurement may bring detailed insight into causes of dispersion,aggregation or flocculation, and can be used to improve formulation ofdispersions, emulsions and suspensions. ζ potential reflects a potentialdifference between dispersion medium and stationary layer of fluidattached to dispersed particles.

Magnitude of ζ potential indicates the degree of electrostatic repulsionbetween adjacent, similarly charged particles in a dispersion. Formolecules and particles that are small enough, a high ζ potentialrelates to stability, generally, a value of at least about −55, at leastabout −65 or lower (greater absolute value) is desirable. The silvercomposite ionomer containing the monomer, silver acrylate, had ameasured ζ potential of −65.5 mV, which indicates stability of thecomposite ionomer particle dispersion.

The interaction between ionic silver and carboxylate groups, which actas ionic crosslinks, may have an effect on the properties of the polymermatrix, such as, solubility in chemical solvents, glass transitiontemperature, molecular weight, and water sensitivity. Representations ofionic crosslinks between ionomer type polymers according to certainembodiments of the disclosure are shown in FIG. 1.

Composite Filament Synthesized from the Metallo Ionomer PolymerNanocomposite

Composite powders as described herein are first prepared from themetallo ionomer polymer nanocomposite, and then the composite powdersare converted to composite filaments by filament fabrication.

Composite powders may be prepared by conventional (ground andclassification) or chemical (emulsion aggregation) means. U.S. Pat. Nos.5,111,998, 5,147,753, 5,272,034, and 5,393,630 disclose conventionaltoner manufacturing processes are incorporated in their entirety byreference herein.

Composite powders may be prepared by emulsion aggregation means. Anysuitable emulsion aggregation procedure may be used in forming theemulsion aggregation composite particles without restriction. The methodto prepare composite powders from the metallo ionomer polymer latex issimilar to the process known to generate toner particles (emulsionaggregation or EA). Particles of narrow size distribution andcontrollable particle size can be achieved with the aid of aggregatingagents such as zinc acetate, magnesium chloride salts, aluminum sulfateand polyaluminum chloride (PAC). The particle morphology can becontrolled via temperature, time, and stirring to provide particles thatrange from an irregularly shaped or an imperfect spherical to a near orperfect spherical.

FIG. 3 shows an emulsion aggregation process for preparing dry particlesfor Fused Deposition Modelling (FDM) according to certain embodiments ofthe present disclosure. These procedures typically include the processsteps of aggregating an emulsion of particles, such as those describedin the present disclosure, a metallo ionomer polymer latex, and one ormore additional optional additives to form aggregated particles,subsequently coalescing the aggregated particles, and then recovering,optionally washing and optionally drying the obtained emulsionaggregation particles. However, in embodiments, the process can bemodified by the addition of a coalescent agent (or coalescence aidagent) prior to the coalescence. This addition of the coalescent agentprovides toner particles having improved spheroidization, and allows thecoalescence to be conducted in a shorter time, at a lower processtemperature, or both. The aggregating step includes heating the slurryto a temperature of from about 30° C. to about 80° C., from about 40° C.to about 70° C., or from about 50° C. to about 68° C. The duration ofthe aggregation step may be from about 1 minute to about 8 hours, fromabout 30 minutes to about 6 hour, or from about 60 minutes to about 4hours. The coalescing step includes heating the aggregated particles toa temperature of from about 30° C. to about 95° C., from about 40° C. toabout 95° C., or from about 60° C. to about 90° C. The duration of thecoalescing step may be from about 1 minute to about 6 hours, from about30 minutes to about 4 hour, or from about 60 minutes to about 3 hours.

Examples of suitable coalescent agents include, but are not limited to,benzoic acid alkyl esters, ester-alcohols, glycol-ether type solvents,long-chain aliphatic alcohols, aromatic alcohols, mixtures thereof, andthe like. Examples of benzoic acid alkyl esters include benzoic acidalkyl esters where the alkyl group, which can be straight or branched,substituted or unsubstituted, has from about 2 to about 30 carbon atoms,such as decyl or isodecyl benzoate, nonyl or isononyl benzoate, octyl orisooctyl benzoate, 2-ethylhexyl benzoate, tridecyl or isotridecylbenzoate, 3,7-dimethyloctyl benzoate, 3,5,5-trimethylhexyl benzoate,mixtures thereof, and the like. Specific commercial examples of suchbenzoic acid alkyl esters include VELTA® 262 (isodecyl benzoate) andVELTA® 368 (2-ethylhexyl benzoate), available from Vlesicol ChemicalCorporation. Examples of ester-alcohols include hydroxyalkyl esters ofalkanoic acids where the alkyls group, which can be straight orbranched, substituted or unsubstituted, independently have from about 2to about 30 carbon atoms, such as 2,2,4-trimethylpentane-1,3-diolmonoisobutyrate. Specific commercial examples of such ester-alcoholsinclude TEXANOL® (2,2,4-trimethylpentane-1,3-diol monoisobutyrate)available from Eastman Chemical Company. Examples of glycol-ether typesolvents include diethylene glycol monomethylether acetate, diethyleneglycol monobutylether acetate, butyl carbitol acetate (BOA), and thelike. Examples of long-chain aliphatic alcohols include those where thealkyl group is from about 5 to about 20 carbon atoms, such asethylhexanol, octanol, dodecanol, and the like. Examples of aromaticalcohols include benzyl alcohol, and the like.

In embodiments, the coalescent agent (or coalescence aid agent)evaporates during later stages of the emulsion aggregation process orduring coalescence, such as during the heating step that is generallynear or above the glass transition temperature of the sulfonatedpolyester resin. The final composite powders are thus free of, oressentially or substantially free of, any remaining coalescent agent. Tothe extent that any remaining coalescent agent may be present in thefinal powder composites, the amount of remaining coalescent agent issuch that it does not affect any properties or performance of thecomposite powders.

The coalescent agent can be added prior to the coalescence (or right atthe beginning prior to heating or aggregation) in any desired orsuitable amount. For example, the coalescent agent can be added in anamount of from about 0.01 to about 10 percent by weight, based on thesolids content in the reaction medium. For example, the coalescent agentcan be added in an amount of from about 0.05 or from about 0.1 to about0.5 or to about 5.0 percent by weight, based on the solids content inthe reaction medium. In embodiments, the coalescent agent can be addedat any time between aggregation and coalescence, or upfront beforeheating.

Optional additives such as waxes, pigments, ceramics, carbon fiber ornanotubes, and fillers may be included in the composite powder. Theseadditives may be added prior to or during the aggregation step orupfront before heating. The amount of additives present in the compositepowder may be from about 0% to about 30%, from about 0% to about 20%, orfrom about 0% to about 10% by weight of the total weight of thecomposite powder. Once the composite powder is converted into thecomposite filament, the additives and amounts of additives stayunchanged.

The method of preparing the composite filament of the present disclosurecomprising polymerizing a first mixture comprising a firststyrene/acrylate copolymer to form a core styrene/acrylate polymer resin(“seed”) in an organic free solvent, heating the core styrene/acrylatepolymer resin; adding a shell styrene/acrylate ionomer resin bypolymerizing a second mixture comprising a second styrene/acrylatecopolymer and initiator to the formed core styrene/acrylate polymerresin to form a shell disposed about the core particles, thereby formingan emulsion of composite particles, wherein the shell styrene/acrylateionomer resin comprises a metal; aggregating the emulsion of compositeparticles to form aggregated particles; coalescing the aggregatedparticles to form coalesced particles; washing the coalesced particles,thereby forming the composite powder; and extruding the composite powderto produce the composite filament. In embodiments, the polymerizing stepto form a core styrene/acrylate polymer resin in an organic-free solventand the emulsifying step including heating the core styrene/acrylatepolymer resin occur simultaneously. In embodiments, the polymerizingstep is performed in an aqueous media. The core styrene/acrylate polymerresin is an emulsion.

The term “organic-free solvent” refers to media that does not containany organic solvent. An aqueous media such as water is considered to bean organic-free solvent.

In embodiments, heating is conducted at a temperature from about 65° C.to about 90° C. Temperatures in this range are appropriate for both theinitial dissolution of the polymer resin and subsequent reduction in thepresence of silver ion.

In embodiments, methods disclosed herein may be particularly well-suitedfor making composites with relatively low solids content. Under suchconditions, silver ion and reducing agent may readily diffuse throughthe polymer matrix. In the case of silver ion, such ready diffusion mayimprove uniformity of distribution of silver throughout the matrix. Thecomposite powders may be then fabricated into filaments. The compositefilament of the present disclosure may be manufactured using anextrusion process. The composite powders may be first loaded into a meltflow index (MFI) instrument (also referred to as an extrusionplastometer) and equilibrated at a temperature of from about 60° C. toabout 250° C., from about 60° C. to about 190° C., or from about 80° C.to about 150° C., for a period of time, such as from about 1 to about 90minutes, from about 1 to about 60 minutes, from about 5 to about 45minutes. After equilibration, the material obtained may be then extrudedwith a weight in a range of from about 1 kg to about 30 kg, from about 1kg to about 20 kg, or from about 2 kg to about 10 kg, through a 0.5-5 mmdiameter die to fabricate the FDM filament. In embodiments, thecomposite filament is in the form of a cylinder with a diameter of, forexample, about 0.5 mm to about 5.0 mm, about 1.5 mm to about 3.0 mm,about 1.75 mm to about 3.0 mm. The length of the composite filament canbe in any length, for example, for testing purposes, from about 2 ft toabout 100 ft, from about 2 ft to about 50 ft, from about 5 ft to about20 ft (, and for commercial purposes, from about 50 ft to 2000 ft, fromabout 300 ft to about 1500 ft, or from about 400 ft to about 1300 ft.

The process of filament fabrication merely changes the physical appearof the composite and does not alter the material or content of thecomposite. Thus, the filament of the present disclosure comprises thesame metallo ionomer polymer nanocomposites described herein. Inembodiments, the filament comprises the same metallo ionomer polymernanocomposites having a core particle and a shell comprising astyrene/acrylate ionomer resin disposed over as described herein, wherethe styrene/acrylate ionomer resin comprises a metal ion acrylatemonomer.

In embodiments, a loading of metal and/or metal ion (in the form of ametal ion methacrylate or acrylate) is present in the compositefilaments in a range from about 0.5 ppm to about 50,000 ppm, from about5 ppm to about 5,000, from about 10 ppm to about 2,500, ppm, or fromabout 50 ppm to about 1,000 ppm. Loading concentrations of metal/metalion within this range can be used for antibacterial applications.

The final composite powders can be of any desired size, in embodiments,the composite powders may have a particle size of from about 10 micronsto about 300 microns, from about 10 microns to about 100 microns, orfrom about 5 microns to about 20 microns. In embodiments, the compositepowders have a particle size distribution with a lower number ratiogeometric standard deviation (GSD) of from about 1.0 to about 4.0, fromabout 1.1 to about 3.0, or from about 1.2 to about 2.0. The finalcomposite powders can be of any desired shape, either coarse orspherical.

The composite filament may have a glass transition temperature (Tg) offrom about −5° C. to about 150° C., from about 20° C. to about 120° C.or from about 40° C. to about 100° C. The composite filament may have athermal conductivity of from about 0.04 W/(mK) to about 50 W/(mK). Thecomposite filament may have a tensile strength of from about 10 MPa toabout 200 MPa. The softening point temperature of the composite filamentas measured by Mettler Cup and Ball Method may be from about 100° C. toabout 250° C. The softening point (Ts) can be measured by using the cupand ball apparatus available from Mettler-Toledo as the FP90 softeningpoint apparatus and using the Standard Test Method (ASTM) D-6090. Themeasurement can be conducted using a 0.50 gram sample and heated from100° C. at a rate of 1° C./min. The composite filament may have a theweight average molecular weight from about 10,000 grams/mole to about500,000 grams/mole. The composite filament may have a Melt Flow Index(MFI) from about 0.5 grams/10 minutes to about 50 grams/10 minutes.(Note—Melt Flow Index (MFI) also known as melt mass flow rate is ananalysis to measure how easily thermoplastic polymers flow. It is anindirect method to measure viscosity where viscosity is inverselyproportional of MFI.)

The properties of the composite filaments herein make them useful invarious applications including, without limitation, electronicscomponents, optical detectors, chemical and biochemical sensors anddevices. The ability to miniaturize any of these materials is a majorbenefit of using the nanoscale composite structures herein. Other areasof interest that employ the composite filament herein include, withoutlimitation, antibacterial applications, optical bi-stability, textilesphotoresponsivity, environmental, biological, medicine (membranes andseparation devices), functional smart coatings, fuel and solar cells,and as catalysts.

The following Examples are being submitted to illustrate embodiments ofthe present disclosure. These Examples are intended to be illustrativeonly and are not intended to limit the scope of the present disclosure.Also, parts and percentages are by weight unless otherwise indicated. Asused herein, “room temperature” refers to a temperature of from about20° C. to about 25° C.

EXAMPLES Example 1

This example describes the preparation of an Emulsion PolymerizationLatex with 1% Silver Methacrylate

A latex emulsion comprised of polymer particles generated from emulsionpolymerization of styrene, n-butyl acrylate and silver methacrylate wasprepared as follows.

A surfactant solution of 0.69 g Dowfax 2A1 (anionic surfactant, Dow) and83.4 g de-ionized water (DIW) was prepared by mixing for 10 min in a 500ml round bottom flask that was placed on an electric heating mantle andpurged with nitrogen. The flask was purged continuously with nitrogenwhile being stirred at 195 rpm. The reactor was heated to 70° C. at acontrolled rate. Separately, 1.52 g of ammonium persulfate (APS)initiator was dissolved in 13.3 g of DIW. Separately, 73.54 g ofstyrene, 27.58 g of butyl acrylate, 1.02 g of silver methacrylate, 1.78g of 1-dodecanethiol (DDT) and 0.36 g of 1,10-decanediol diacrylate(ADOD) were added to a premix of 3.91 g of Dowfax 2A1 in 44.68 g of DIWand mixed to form an emulsion. Then, 7.44% of the above emulsion (7.63g) was dropped slowly into the reactor containing the aqueous surfactantphase at 70° C. to form, “seeds,” while being purged with nitrogen. Theinitiator solution was charged slowly into the reactor. The monomeremulsion feed then was started and added over 140 min. Once all themonomer emulsion was charged into the reactor flask, the stirring wasincreased to 210 rpm and the temperature was held at 70° C. overnight(approximately 20 hrs) to complete the reaction. The heat was turned offand the latex was left to cool while stirring. The product then wassieved through a 25 μm screen.

A schematic of mechanism of bulk emulsion polymerization of latexparticles containing silver-based monomer is shown in FIG. 2.

Table 1 summarizes the content and quantity of the ingredients used inthe emulsion polymerization.

TABLE 1 % % rel. to relative total grams to total monomer Styrene 73.5428.35% 71.75% nButyl Acrylate 27.58 10.63% 26.91% Silver Methacrylate1.02 0.39% 1.00% 1,10-decanediol diacrylate 0.36 0.14% 0.35% Dowfax 2A1(aqueous) 0.69 0.27% 0.67% Dowfax 2A1 (monomer) 3.91 1.51% 3.81%n-dodecanethiol (DDT) 1.78 0.69% 1.74% Water (aqueous phase) 83.4032.15% Water (monomer phase) 44.68 17.22% Seed (from initial) 7.63 2.94%7.44% APS 1.52 0.59% 1.48% Water (in initiator solution) 13.30 5.13%Total (grams) 259.41 102.50

The particle size was measured by NANOTRAC U2275E particle size analyzerand found to have a D50 of 83.2 nm and D95 of 127.6 nm. The solidscontent was 35.15%.

Examples 2 and 3

These two examples describe the preparation of styrene/N-butyl acrylatecore silver/methyl methacrylate shell latexes using sodium dodecylsulfate (SDS)

For the initial solution for both examples, sodium dodecyl sulfate (SDS)was dissolved in dH2O in a three-necked round-bottom flask equipped witha reflux condenser, overhead stirrer and nitrogen exit and heated to 70°C. (200 RPM). The core monomer mixture was prepared by adding styrene,n-butyl acrylate and dodecanethiol (DDT) to a beaker. SLS was dissolvedin deionized water (dH₂O) and added to the core monomer mixture. Themonomer was emulsified with rapid mechanical stirring for 5 minutesfollowed by rest for 5 minutes, and repeated twice for a total of threetimes. 7.71 g of the core monomer mixture for from Example 2 and 4.61 gof the core monomer mixture from Example 3, as shown in Table 2, wereadded to their respective reactors as a seed. The initiator for bothexamples were prepared by dissolving 1.38 g potassium persulfate (KPS)and 0.74 g sodium bicarbonate in 13.0 g dH₂O and added to the respectivereactors dropwise. The remaining core monomer emulsion was fed into thereactor by pump at a rate of 0.7 g/min. The shell monomer mixture wasprepared by dissolving Ag methacrylate in methyl methacrylate and addingDDT. SDS was dissolved in dH₂O and added to the shell monomer mixture.The shell monomer was emulsified with rapid mechanical stirring for 5minutes followed by rest for 5 minutes, repeated twice for a total ofthree times. 2.17 g of the shell monomer mixture from Example 2 and 1.00g of the shell monomer mixture from Example 3 was added to therespective reactors as a seed. The initiator for both Example 2 and 3were prepared by dissolving 0.35 g KPS and 0.184 g sodium bicarbonate in3.3 g dH₂O and added to the respective reactor dropwise. The remainingshell monomer emulsion was added to the respective reactor dropwise (240RPM). The reaction was allowed to proceed at 70° C. overnight (200 RPM)before the latex was cooled to room temperature and sieved through a 25μm sieve. The final appearance of both latexes was a dark grey opaqueemulsion.

Table 2 summaries the content and quantities of the reactants.

TABLE 2 Example 2 Example 3 Component (in grams) (in grams) InitialSolution SLS 2.520 1.89 dH₂O 81.20 85.5 Core Monomer styrene 41.00 71.75N-butyl acrylate 51.25 20.50 DDT 2.38 2.38 dH₂O 43.53 44.19 SLS 5.874.40 Seed amount removed Core Seed 7.71 4.61 from Core Monomer EmulsionInitiator Mixture for Core KPS 1.38 1.38 Seed NaHCO₃ 0.74 0.74 dH₂O 13.013.0 Shell Monomer Ag Methacrylate 1.00 1.00 Methyl 9.23 9.23methacrylate DDT 0.42 0.42 dH₂O 10.0 10.0 SLS 1.0 1.0 Seed amountremoved Shell Seed 2.17 1.00 from Shell Monomer Emulsion InitiatorMixture for Shell KPS 0.35 0.35 Seed NaHCO₃ 0.184 0.184 dH₂O 3.30 3.30

The results in Table 3 provides the analytical data of the three latexessynthesized with silver methacrylate in Examples 1-3. As shown, thelatex of Example 1 demonstrates a very large molecular weight ascompared to that of Examples 2 and 3. Chain entanglements of the polymermay be due to the ionic interactions that contribute to physicalcross-links in the polymer chains. This phenomenon is seen in the bulkEP process versus the core/shell EP process due to the positioning ofthe ionomer throughout the whole polymer in the bulk formulation inExample 1 as opposed to being selectively added to the shell only as inExample 2 and 3.

TABLE 3 Measurement Example 1 Example 2 Example 3 Solids Content (%)35.15 29.49 22.01 D50 Particle Size (Nanometers) 83.2 42.1 43.9 Zetapotential (mV) −64.5 −82.4 −63.6 Zeta deviation (mV) 12.5 10.5 12.8Silver content by ICP (ppm) 33.8 204.2 310.2 Tg (onset) 51.84° C. 93.47°C. 43.26° C. Molecular Weight 189,304 20,378 14,989

Example 4

This example shows the preparation of a pre-filament powder

In a 2 L glass reactor, a latex emulsion containing 200 g of silveracrylate-based copolymer obtained from Example 1 and 200 g of deionizedwater is premixed to give total solids of 17.6%, the pH is adjusted fromabout 2.0 to 3.0 with 1 M NaOH. The slurry is then homogenized using anIKA ULTRA TURRAX T50 homogenizer operating at about 3,000-4,000 RPM.During homogenization about 28 g of a flocculent mixture containingabout 2.8 g polyaluminum chloride mixture and about 25.2 g 0.02 M nitricacid solution is added to the slurry. Thereafter, the 2 L glass reactoris transferred to a heating mantle; the RPM is set to 230 and heated toa temperature of about 50° C. where samples are taken to determine theaverage particle size. Once the particle size of the slurry is about 15microns as measured with a Coulter Counter is achieved, freezing beginswith the pH of the slurry being adjusted to about 4.5-5.0 using a 4%NaOH solution while also decreasing the reactor RPM to 75. The reactortemperature is ramped to 96° C. Once at the coalescence temperature, theslurry is coalesced for about 3 hours until the particle circularity isbetween 0.975-0.980 as measured by the Flow Particle Image Analysis(FPIA) instrument. The slurry is then cooled. The final particle size ofthe slurry is about 15.5 microns, GSDv 1.25, GSDn 1.25 and a circularityof 0.981. The slurry is then discharged from the reactor and theparticles are filtered from the mother liquor and washed 2 times withdeionized water (DIW). The final slurry is re-dispersed into 200 mL ofdeionized water, frozen via shell-freezer, and placed on drier for 3days to result in dry particles to be used for filament fabrication inExample 5.

Example 5

This Example shows the fabrication of filaments

The dried particles obtained from Example 4 were fed into the melt flowindex (MFI) instrument (extrusion plastometer) and equilibrated at 90°C. for 6 minutes. The material was then extruded with a 17 kg weightthrough a 2 mm diameter die to fabricate the FDM filament forantibacterial testing.

Example 6

This Example shows the antibacterial testing of filaments

A 200 mm Pyrex® glass tube is filled with Bacto™ Tryptic Soy Broth and afilament from Example 5 is placed in the glass tube. The glass tube issealed with a rubber stopper and being incubated at 37° C. and 90%humidity for 14 days. A control sample of styrene acrylate-basedfilament (from Example 1) containing no AgNPs is also treated to thesame incubation procedure. After the incubation period, the tubes arevisually analyzed for turbidity. Prior to any filament incubation, thesoy broth or TSB was transparent. Once the TSB is exposed to bacteria orfungi, the organisms will turn the liquid turbid due toreproduction/multiplication of bacteria. Another indicator of bacterialgrowth is accumulation of precipitation that will settle to the bottomof the test tube. The filament made with the silver acrylate-basedcopolymer in Example 5 shows no signs of bacterial contamination whilethe filament made from a control sample of Example 1 (but with no Agacrylate monomer) show both turbidity and precipitation indicating alack of antibacterial activity.

Example 7

This example demonstrates the antibacterial activities of aqueous-basedlatexes according to embodiments of the present disclosure.

To test antibacterial properties suspensions made from latexes ofExamples 2 and 3 were dip-coated onto different substrates (VWR410qualitative filter paper and Whatman 6 qualitative filter paper). Thesolvent was evaporated and the substrate was placed onto an inoculatedpetri dish containing general purpose powdered medium for thecultivation of less fastidious microorganisms (nutrient agar; N0394FLUKA). The dish was incubated overnight at 37° C. After 24 hours, largezones of inhibition were observed for both suspensions made from latexin Example 2 (top half) and Example 3 (bottom half) on the twosubstrates: VWR410 qualitative filter paper (left) and Whatman 6qualitative filter paper (right). (FIG. 4).

What is claimed is:
 1. A composite filament comprising: a core particlecomprising a styrene/acrylate polymer resin and optionally a first metalion acrylate monomer; and a shell comprising a styrene/acrylate ionomerresin, wherein the styrene/acrylate ionomer resin comprises a secondmetal ion acrylate monomer; wherein the total amount of metal presentedin the composite filament ranges in a concentration of from about 0.5ppm to about 50,000 ppm; and further wherein the composite filament hasa diameter of from about 0.5 mm to about 5 mm.
 2. The composite filamentof claim 1, wherein the first metal of the shell comprises a silver. 3.The composite filament of claim 1, wherein the styrene/acrylate ionomerresin of the shell comprises a silver monomer selected from a silveracrylate monomer, a silver methacrylate monomer or combinations thereof.4. The composite filament of claim 3, wherein the silver monomer ispresent in the shell resin from about 0.01% to about 10% by weight ofthe total monomers.
 5. The composite filament of claim 1, wherein thestyrene/acrylate ionomer resin of the shell comprises a co-monomerselected from methyl methacrylate, butyl acrylate, diacrylate,cyclohexyl methacrylate, styrene, methacrylic acid, dimethylaminoethylmethacrylate or combinations thereof.
 6. The composite filament of claim1, wherein the styrene/acrylate polymer resin of the core is selectedfrom the group consisting of styrene acrylates, styrene butadienes,styrene methacrylates, and combinations thereof.
 7. The compositefilament of claim 6, wherein the styrene/acrylate polymer resin of thecore is selected from the group consisting of poly(styrene-alkylacrylate), poly(styrene-1,3-diene), poly(styrene-alkyl methacrylate),poly(styrene-alkyl acrylate-acrylic acid),poly(styrene-1,3-diene-acrylic acid), poly(styrene-alkylmethacrylate-acrylic acid), poly(alkyl methacrylate-alkyl acrylate),poly(alkyl methacrylate-aryl acrylate), poly(aryl methacrylate-alkylacrylate), poly(alkyl methacrylate-acrylic acid), poly(styrene-alkylacrylate-acrylonitrile-acrylic acid),poly(styrene-1,3-diene-acrylonitrile-acrylic acid), poly(alkylacrylate-acrylonitrile-acrylic acid), poly(styrene-butadiene),poly(methylstyrene-butadiene), poly(methyl methacrylate-butadiene),poly(ethyl methacrylate-butadiene), poly(propyl methacrylate-butadiene),poly(butyl methacrylate-butadiene), poly(methyl acrylate-butadiene),poly(ethyl acrylate-butadiene), poly(propyl acrylate-butadiene),poly(butyl acrylate-butadiene), poly(styrene-isoprene),poly(methylstyrene-isoprene), poly(methyl methacrylate-isoprene),poly(ethyl methacrylate-isoprene), poly(propyl methacrylate-isoprene),poly(butyl methacrylate-isoprene), poly(methyl acrylate-isoprene),poly(ethyl acrylate-isoprene), poly(propyl acrylate-isoprene),poly(butyl acrylate-isoprene), poly(styrene-propyl acrylate),poly(styrene-butyl acrylate), poly(styrene-butadiene-acrylic acid),poly(styrene-butadiene-methacrylic acid),poly(styrene-butadiene-acrylonitrile-acrylic acid), poly(styrene-butylacrylate-acrylic acid), poly(styrene-butyl acrylate-methacrylic acid),poly(styrene-butyl acrylate-acrylonitrile), poly(styrene-butylacrylate-acrylonitrile-acrylic acid), poly(styrene-butadiene),poly(styrene-isoprene), poly(styrene-butyl methacrylate),poly(styrene-butyl acrylate-acrylic acid), poly(styrene-butylmethacrylate-acrylic acid), poly(butyl methacrylate-butyl acrylate),poly(butyl methacrylate-acrylic acid), poly(acrylonitrile-butylacrylate-acrylic acid) and combinations thereof.
 8. The compositefilament of claim 1 having a glass transition temperature (Tg) of fromabout −5° C. to about 150° C.
 9. The composite filament of claim 1having a thermal conductivity of from about 0.04 W/(mK) to about 50W/(mK).
 10. The composite filament of claim 1 having a tensile strengthof from about 10 MPa to about 200 MPa.
 11. The composite filament ofclaim 1 further comprises an additive selected from the group consistingof a wax, a pigment, a ceramic, a carbon fiber, a nanotube, or acombination thereof.
 12. A method of producing a composite filament,comprising: polymerizing a first mixture comprising a firststyrene/acrylate copolymer to form a core styrene/acrylate polymer resinin an organic-free solvent; heating the core styrene/acrylate polymerresin; adding a shell styrene/acrylate ionomer resin by polymerizing asecond mixture comprising a second styrene/acrylate copolymer andinitiator to the formed polymer core styrene/acrylate polymer resin toform a shell disposed about the core styrene/acrylate polymer resin,thereby forming an emulsion of composite particles, wherein the shellstyrene/acrylate ionomer resin comprises a metal; aggregating theemulsion of composite particles to form aggregated particles; coalescingthe aggregated particles to form coalesced particles; washing thecoalesced particles, thereby forming the composite powder; and extrudingthe composite powder to produce the composite filament.
 13. The methodof claim 11, wherein the metal is silver, copper, gold, palladium, ormixtures thereof
 14. The method of claim 11, wherein thestyrene/acrylate ionomer resin of the shell comprises a silver monomerselected from a silver acrylate monomer, a silver methacrylate monomeror combinations thereof.
 15. The method of claim 11, wherein the corecomprising a styrene/acrylate polymer resin selected from the groupconsisting of poly(styrene-alkyl acrylate), poly(styrene-1,3-diene),poly(styrene-alkyl methacrylate), poly(styrene-alkyl acrylate-acrylicacid), poly(styrene-1,3-diene-acrylic acid), poly(styrene-alkylmethacrylate-acrylic acid), poly(alkyl methacrylate-alkyl acrylate),poly(alkyl methacrylate-aryl acrylate), poly(aryl methacrylate-alkylacrylate), poly(alkyl methacrylate-acrylic acid), poly(styrene-alkylacrylate-acrylonitrile-acrylic acid),poly(styrene-1,3-diene-acrylonitrile-acrylic acid), poly(alkylacrylate-acrylonitrile-acrylic acid), poly(styrene-butadiene),poly(methylstyrene-butadiene), poly(methyl methacrylate-butadiene),poly(ethyl methacrylate-butadiene), poly(propyl methacrylate-butadiene),poly(butyl methacrylate-butadiene), poly(methyl acrylate-butadiene),poly(ethyl acrylate-butadiene), poly(propyl acrylate-butadiene),poly(butyl acrylate-butadiene), poly(styrene-isoprene),poly(methylstyrene-isoprene), poly(methyl methacrylate-isoprene),poly(ethyl methacrylate-isoprene), poly(propyl methacrylate-isoprene),poly(butyl methacrylate-isoprene), poly(methyl acrylate-isoprene),poly(ethyl acrylate-isoprene), poly(propyl acrylate-isoprene),poly(butyl acrylate-isoprene), poly(styrene-propyl acrylate),poly(styrene-butyl acrylate), poly(styrene-butadiene-acrylic acid),poly(styrene-butadiene-methacrylic acid),poly(styrene-butadiene-acrylonitrile-acrylic acid), poly(styrene-butylacrylate-acrylic acid), poly(styrene-butyl acrylate-methacrylic acid),poly(styrene-butyl acrylate-acrylonitrile), poly(styrene-butylacrylate-acrylonitrile-acrylic acid), poly(styrene-butadiene),poly(styrene-isoprene), poly(styrene-butyl methacrylate),poly(styrene-butyl acrylate-acrylic acid), poly(styrene-butylmethacrylate-acrylic acid), poly(butyl methacrylate-butyl acrylate),poly(butyl methacrylate-acrylic acid), poly(acrylonitrile-butylacrylate-acrylic acid) and combinations thereof.
 16. The method of claim11, wherein the aggregating is conducted at a temperature of from about30° C. to about 80° C.
 17. The method of claim 11, wherein thecoalescing is conducted at a temperature of from about 30° C. to about95° C.
 18. An article comprising: a composite filament comprising: acore particle comprising a styrene/acrylate polymer resin and optionallya first metal ion acrylate monomer; and a shell comprising astyrene/acrylate ionomer resin, wherein the styrene/acrylate ionomerresin comprises a second metal ion acrylate monomer; wherein the totalamount of metal presented in the composite filament ranges in aconcentration of from about 0.5 ppm to about 50,000 ppm; and furtherwherein the composite filament has a diameter of from about 0.5 mm toabout 5 mm.
 19. The article of claim 18, wherein, wherein thestyrene/acrylate polymer resin of the core is selected from the groupconsisting of poly(styrene-alkyl acrylate), poly(styrene-1,3-diene),poly(styrene-alkyl methacrylate), poly(styrene-alkyl acrylate-acrylicacid), poly(styrene-1,3-diene-acrylic acid), poly(styrene-alkylmethacrylate-acrylic acid), poly(alkyl methacrylate-alkyl acrylate),poly(alkyl methacrylate-aryl acrylate), poly(aryl methacrylate-alkylacrylate), poly(alkyl methacrylate-acrylic acid), poly(styrene-alkylacrylate-acrylonitrile-acrylic acid),poly(styrene-1,3-diene-acrylonitrile-acrylic acid), poly(alkylacrylate-acrylonitrile-acrylic acid), poly(styrene-butadiene),poly(methylstyrene-butadiene), poly(methyl methacrylate-butadiene),poly(ethyl methacrylate-butadiene), poly(propyl methacrylate-butadiene),poly(butyl methacrylate-butadiene), poly(methyl acrylate-butadiene),poly(ethyl acrylate-butadiene), poly(propyl acrylate-butadiene),poly(butyl acrylate-butadiene), poly(styrene-isoprene),poly(methylstyrene-isoprene), poly(methyl methacrylate-isoprene),poly(ethyl methacrylate-isoprene), poly(propyl methacrylate-isoprene),poly(butyl methacrylate-isoprene), poly(methyl acrylate-isoprene),poly(ethyl acrylate-isoprene), poly(propyl acrylate-isoprene),poly(butyl acrylate-isoprene), poly(styrene-propyl acrylate),poly(styrene-butyl acrylate), poly(styrene-butadiene-acrylic acid),poly(styrene-butadiene-methacrylic acid),poly(styrene-butadiene-acrylonitrile-acrylic acid), poly(styrene-butylacrylate-acrylic acid), poly(styrene-butyl acrylate-methacrylic acid),poly(styrene-butyl acrylate-acrylonitrile), poly(styrene-butylacrylate-acrylonitrile-acrylic acid), poly(styrene-butadiene),poly(styrene-isoprene), poly(styrene-butyl methacrylate),poly(styrene-butyl acrylate-acrylic acid), poly(styrene-butylmethacrylate-acrylic acid), poly(butyl methacrylate-butyl acrylate),poly(butyl methacrylate-acrylic acid), poly(acrylonitrile-butylacrylate-acrylic acid) and combinations thereof.
 20. The article ofclaim 18, wherein the article is selected from the group consisting of abiochemical sensor, an optical detector, an antibacterial, a textile, acosmetic, an electronic component, a fiber, and a cryogenicsuperconducting material.